Light-induced reduction of cytoplasmic free calcium in retinal rod outer segment

King Wai Yau, Kei Nakatani

Research output: Contribution to journalArticle

Abstract

The response of retinal rod photoreceptors to light consists of a membrane hyperpolarization resulting from the decrease of a light-sensitive conductance in the outer segment1. According to the calcium hypothesis, this conductance is blocked by a rise in intracellular free Ca triggered by light2, a notion supported by the findings that an induced rise in internal Ca leads to blockage of the light-sensitive conductance3-9 and that light triggers a net Ca efflux from the outer segment via a Na-Ca exchanger, suggesting a rise in internal free Ca in the light10-13. We have now measured both Ca influx and efflux through the outer segment plasma membrane and find that, contrary to the calcium hypothesis, light seems to decrease rather than increase the free Ca concentration in the rod outer segment. This result implies that Ca does not mediate visual excitation but it probably has a role in light adaptation.

Original languageEnglish (US)
Pages (from-to)579-582
Number of pages4
JournalNature
Volume313
Issue number6003
DOIs
StatePublished - 1985
Externally publishedYes

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Retinal Photoreceptor Cell Outer Segment
Rod Cell Outer Segment
Retinal Rod Photoreceptor Cells
Calcium
Light
Ocular Adaptation
Cell Membrane
Membranes

ASJC Scopus subject areas

  • General

Cite this

Light-induced reduction of cytoplasmic free calcium in retinal rod outer segment. / Yau, King Wai; Nakatani, Kei.

In: Nature, Vol. 313, No. 6003, 1985, p. 579-582.

Research output: Contribution to journalArticle

Yau, King Wai ; Nakatani, Kei. / Light-induced reduction of cytoplasmic free calcium in retinal rod outer segment. In: Nature. 1985 ; Vol. 313, No. 6003. pp. 579-582.
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